1. FIELD OF THE INVENTION
This invention relates to formulations and methods for preparing such formulations for coloring materials for cement and concrete products. In particular, it relates to such formulations and methods for forming thixotropic stabilized suspensions of such pigment particles which resist settling out.
2. PRIOR ART
Conventional cement or concrete coloring compositions comprise powders which are added by hand or by a screw conveyor in their dry state to a wet concrete or cement mix in a mixing apparatus. It is difficult to accurately add desired amounts of such powders to the wet concrete mix and there is often waste of such coloring material. Furthermore, with powders it is difficult to obtain a sufficiently thorough mixing of the powders into the wet cement mix so as to achieve a homogeneous color throughout the mixture. Conventional methods also require the concrete or cement contractor to maintain large inventories of the coloring composition and involve certain health hazards as well.
It is highly desirable to have a system for coloring wet cement and concrete mixes by the addition of the coloring material in a liquid form to the mix.
It is also desirable to have a system in which the coloring material may be added by liquid pumps to the wet concrete mix.
It would also be highly advantageous to have a suspension of color pigment material which will not settle out within a relatively short time.
It is another object of the present invention to provide a liquid slurry or mixture of particulate color pigments for each of several colors which can easily be mixed with one another or with a wet cement mix by the user to obtain a full range of composite colors.
Still another object of the invention is to provide a system for adding pigment material to cement and concrete mixtures which can be automated to a greater extent than has heretofore been the case.
These and other objects of the present invention, which will appear to one skilled in the art upon perusal of the present specification, the drawings, and the claims herein, are attained by the use of the formulas and processes as explained hereinbelow.